You can change password on server via remote desktop. You can follow below steps:
- Login to windows server via Remote Desktop.
- Here click on windows icon and then type Administrative Tools.
- Now click on “Computer Management” and expand “Local Users and Groups”.
- Click on “Users” and right click on “Administrator”.
- You can find option “Set password”, click on it and proceed.
- You will find two fields to enter password, you have to enter new password in both fields and then click on “OK”.